How can I use Spring Boot auto-configured beans in XML configuration files?

Question 1

How can I use Spring Boot auto-configured beans in XML configuration files?

spring spring-integration spring-boot

ccampo · Aug 26, 2014 · Viewed 54.9k times · Source

Answer

Answer

The following sample code worked for me.

Main Application

package app;

import org.springframework.boot.SpringApplication;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.util.Assert;

import javax.sql.DataSource;

public class Application {

    public static void main(String[] args) {
        ConfigurableApplicationContext context = SpringApplication.run(Config.class);
        DataSource dataSource = context.getBean("dataSource", DataSource.class);
        Assert.notNull(dataSource);
    }

}

Spring Java Config

package app;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.*;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;

import javax.sql.DataSource;

@Configuration
@EnableAutoConfiguration
@EnableJpaRepositories
@ComponentScan
@ImportResource("classpath:config.xml")
public class Config {

    @Autowired
    private DataSource dataSource;

}

BarService

package app.service;

import org.springframework.util.Assert;
import javax.annotation.PostConstruct;
import javax.sql.DataSource;

public class BarService {

    private DataSource dataSource;

    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
    }

    @PostConstruct
    public void init() {
        Assert.notNull(dataSource);
    }
}

FooService

package app.service;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.Assert;

import javax.annotation.PostConstruct;
import javax.sql.DataSource;

@Service
public class FooService {

    @Autowired
    DataSource dataSource;

    @PostConstruct
    public void init() {
        Assert.notNull(dataSource);
    }

}

config.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="barService" class="app.service.BarService">
        <property name="dataSource" ref="dataSource"/>
    </bean>

</beans>

Question 2

I'd like to take advantage of some of the Spring Boot auto-configured beans in XML configuration files, but I keep running into exceptions and errors when I try to do so.

For example, if I have data-related libraries on my class path, Spring Boot will auto-configure a DataSource object which I can autowire into my own beans and classes, like so:

@Configuration
@ImportResource("classpath:xmlconfig.xml")
public class Config {

    // This works!!
    @Autowired
    private DataSource dataSource;

    @Bean
    public ClassThatRequiresADataSource() {
        ClassThatRequiresADataSource foo = new ClassThatRequiresADataSource();
        foo.setDataSource(dataSource);
        return foo;
    }
}

However, if I try to do the same in an XML configuration file, I will get an exception. I have been bootstrapping the XML config file by added an @ImportResource("classpath:xmlconfig.xml") to my main configuration class. Here's an example of what I'm talking about... Inside xmlconfig.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <!-- THIS DOES NOT WORK! -->
    <bean id="anotherClassThatRequiresADataSource" class="my.package.AnotherClassThatRequiresADataSource">
        <property name="dataSource" ref="dataSource"/>
    </bean>

</beans>

The above will give an exception when running the Spring Boot app, despite dataSource being a valid, auto-configured Bean name. I've also tried this with the auto-configured ConnectionFactory (with ActiveMQ on the class path) and EntityManagerFactory with Hibernate & JPA on the class path, and none of this works.

Basically, what I'm asking is: what is the equivalent to autowiring Spring Boot auto-configured beans into an XML configuration file?

Here's my main Spring Boot entry point is just the standard class listed in all the docs:

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class Application {

    public static void main(String[] args) throws Exception {
        SpringApplication.run(Application.class, args);
    }
}

I'm mainly using this in a Spring Integration application, where Java Configuration isn't well supported yet and the core of the framework is XML config based, but I'd like to use the Spring Boot auto-configured DataSource and ConnectionFactory beans in some of the integration elements.

EDIT: The answer provided by @AdilF works for the dataSource bean, but a similar configuration does not work for the connectionFactory bean. Please see the following GitHub project for demo code that illustrates this:

https://github.com/ccampo133/autoconfig-test/tree/master

If anybody could figure out how to properly wire the connectionFactory bean, I would greatly appreciate it.

Here's most of the code illustrating this:

Application.java

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

Config.java

@Configuration
@ImportResource("classpath:/resources/config.xml")
public class Config { }

FooService.java

@Service
public class FooService {

    final private Logger logger = LoggerFactory.getLogger(FooService.class);

    @Autowired
    private DataSource dataSource;

    @Autowired
    private ConnectionFactory connectionFactory;

    @Autowired
    private EntityManagerFactory entityManagerFactory;

    @PostConstruct
    public void init() {
        Assert.notNull(dataSource, "dataSource is null!");
        logger.info("dataSource not null");

        Assert.notNull(connectionFactory, "connectionFactory is null!");
        logger.info("connectionFactory not null");

        Assert.notNull(entityManagerFactory, "entityManagerFactory is null!");
        logger.info("entityManagerFactory is not null");
    }
}

BarService.java

public class BarService {

    final private Logger logger = LoggerFactory.getLogger(BarService.class);

    private DataSource dataSource;

    private ConnectionFactory connectionFactory;

    private EntityManagerFactory entityManagerFactory;

    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
    }

    public void setConnectionFactory(ConnectionFactory connectionFactory) {
        this.connectionFactory = connectionFactory;
    }

    public void setEntityManagerFactory(final EntityManagerFactory entityManagerFactory) {
        this.entityManagerFactory = entityManagerFactory;
    }

    @PostConstruct
    public void init() {
        Assert.notNull(dataSource, "dataSource is null!");
        logger.info("dataSource not null");

        Assert.notNull(connectionFactory, "connectionFactory is null!");
        logger.info("connectionFactory not null");

        Assert.notNull(entityManagerFactory, "entityManagerFactory is null!");
        logger.info("entityManagerFactory is not null");
    }
}

config.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="barService" class="app.service.BarService">
        <!-- THIS WORKS! -->
        <property name="dataSource" ref="dataSource"/>

        <!-- THIS DOESN'T WORK! -->
        <property name="connectionFactory" ref="connectionFactory"/>
        <property name="entityManagerFactory" ref="entityManagerFactory"/>
    </bean>

</beans>

build.gradle

buildscript {
    ext {
        junitVersion = "4.11"
        springBootVersion = "1.1.5.RELEASE"
        springIntegrationVersion = "4.0.3.RELEASE"
        activeMqVersion = "5.7.0"
    }

    repositories {
        mavenCentral()
    }

    dependencies {
        classpath "org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}"
    }
}

apply plugin: "java"
apply plugin: "eclipse"
apply plugin: "idea"
apply plugin: "spring-boot"

configurations {
    providedRuntime
}

jar {
    baseName = "autoconfig-test"
    version = "0.0.1-SNAPSHOT"
}

repositories {
    mavenCentral()
    maven { url "http://repo.spring.io/libs-milestone/" }
}

dependencies {
    // Spring Boot starters
    compile "org.springframework.boot:spring-boot-starter-data-jpa:${springBootVersion}"
    compile "org.springframework.boot:spring-boot-starter-integration:${springBootVersion}"
    compile "org.springframework.integration:spring-integration-jms:${springIntegrationVersion}"

    // ActiveMQ
    compile "org.apache.activemq:activemq-core:${activeMqVersion}"

    // Persistence
    runtime "com.h2database:h2"

    // Test
    testCompile "junit:junit:${junitVersion}"
}

How can I use Spring Boot auto-configured beans in XML configuration files?

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